World Area Forecast System (WAFS) - upcoming changes

Probabilistic WAFS forecasts

The WAFC’s are planning to introduce probabilistic WAFS hazard data sets in November 2027, which will become fully operational in November 2028. 

They are expected to consist of the following:

• Probability that the Turbulence Severity will have an Eddy Dissipation rate higher than some set thresholds (equating to moderate or greater in intensity)
• Probability that the Icing Severity will be Moderate or greater in intensity
• Probability that the cumulonimbus cloud tops will exceed height thresholds.
• Initially there will be 6 turbulence levels, and 5 icing levels provided at a horizontal resolution of 0.5 degrees. Data will be provided for the 6-hour to 48-hour forecast period at 3-hour intervals.

Some preliminary example plots are shown below:

1) Probability that the Turbulence Severity Eddy Dissipation rate will exceed 0.2.

2) Probability that the Icing Severity will be moderate or greater in intensity

3) Probability that the cumulonimbus cloud tops will exceed 35,000ft.